A New Architecture for AlGaN/GaN HEMT Frequency Doubler Using Active Integrated Antenna Design Approach

This paper presents a new architecture for an AlGaN/GaN HEMT frequency doubler using the active integrated antenna design approach. A microstrip patch antenna designed at the second harmonic is integrated with the HEMT. The antenna operates as a fundamental frequency reflector in this circuit. Using AlGaN/GaN with 1mm gate periphery, a 4 8 GHz frequency doubler was designed by the suggested design methodology, fabricated, and tested. For the AlGaN/GaN HEMT frequency doubler integrated with the patch antenna, conversion gain of 5 dB and output power of 25 dBm were achieved in pinch-off region with a drain voltage of 12 V.